煤矿安全2025，Vol.56Issue(4)：174-182,9.DOI:10.13347/j.cnki.mkaq.20241572
准东煤田烧变岩水瞬变电磁探测频率探讨
Discussion on transient electromagnetic detection transmitting frequency of groundwater in fire-burned rock in Jundong coalfield
摘要
Abstract
In order to determine the optimal transmitting frequency when we use transient electromagnetic method to detect ground-water in fire-burned rock in Jundong Coalfield,theoretical analysis,forward and inverse calculation and field test are used to con-duct comparative analysis on the effects of rising edge time,formation resistivity and transmitting frequency,respectively.The res-ults show that:the strata in Jundong Coal Field have low resistivity(about 10-40 Ω·m),and the groundwater in fire-burned rock has ultra-low resistivity(about 4.0 Ω·m).When the transmitting frequency is too high,it is easy to affect the transient electromagnetic secondary field signal because the field construction time is too short.In particular,the induced signal strength weakens with the in-crease of the rising edge time,and this effect is more obvious when the formation resistivity decreases.The forward and inversion results show that both 25.0 Hz and 8.3 Hz transmitting frequencies can reflect the induced signal of groundwater in fire-burned rock,but the 25.0 Hz result is weaker than that of 8.3 Hz.The field test found that at the shutdown time of 25.0 Hz transmitting frequency,the ground still had residual induction field,which did not meet the requirements of transient electromagnetic technology.The geo-electric section corresponding to the inversion was inconsistent with the actual situation and did not reflect the rich water area in fire-burned rock.However,there was no such problem at 8.3 Hz transmitting frequency.It is concluded that the transient electromagnet-ic method cannot obtain accurate detection results when the transmitting frequency is too high in Jundong Coal Field.When the transmitting frequency of 8.3 Hz is matched with the combined parameters of 400 m×400 m emission loop and 11 A emission cur-rent,the distribution of fired rock water can be accurately reflected.The combined parameters can be used for reference and promo-tion in mining areas with similar geological conditions.The factors that determine the optimal transmitting frequency are the time of field construction,the depth of detection and the working efficiency,and the transmitting frequency should be selected as high as possible on the basis of sufficient time of field construction and observation.关键词
准东煤田/煤田地质勘探/瞬变电磁法/低电阻率/烧变岩水/工作频率Key words
Jundong Coal Field/geological exploration of coal field/transient electromagnetic method/low resistivity/groundwa-ter in fire-burned rock/transmitting frequency分类
矿业与冶金引用本文复制引用
王强,依力哈木江·吐尼亚孜,范旭东,凌飞,李思维,樊利强,刘源,王鹏,何波,王超,郑曦..准东煤田烧变岩水瞬变电磁探测频率探讨[J].煤矿安全,2025,56(4):174-182,9.基金项目
陕西省自然科学基础研究计划一般资助项目(2024JC-YBMS-200) （2024JC-YBMS-200）
